Abstract/Summary This R24 application for an NIGMS National and Regional Resource is to enable researchers in the under- served area of glycosciences and whose research needs glycoscience expertise, to have continued and improved access to state-of-the-art technologies to advance biomedical research and human health involving protein-glycan interactions and glycan recognition. Glycosylation is the most common and varied post- translational modification (PTM) in all living things, and each cell and organism generates unique PTMs and also glycolipids. Such resources proposed here are neither available to individual laboratories, nor are these specific technologies available commercially. With a base of ~7,000 users (83.6% new users) and hundreds of laboratories utilizing NCFG databases and resources, respectively, related to functional glycomics, our resource is obviously well used and represents a unique resource democratically accessible to all biomedical researchers. The increasing demand is evidenced by the nearly 10,000 individual, different glycan microarrays used at the NCFG resource center in just the last 4 years. Our emphasis on protein-glycan interactions is timely because research continues to uncover clues that these interactions are key to understanding the expression and functions of glycans in biological systems and their recognition by antibodies, glycan-binding proteins (GBPs) and lectins, in human and animal systems, and by microbial pathogens and gut microbiome. Our resource makes available an incredible variety of glycan microarray technologies, glycan libraries, and multiple databases not available elsewhere. The success of our resource has resulted in over a hundred publications by users in the past 5 years. Because of its success and rapidly increasing number of requests, and because we are the only resource of this kind available in the glycosciences, we propose three Specific Aims to continue making these invaluable resources accessible. Aim 1- We will continue to generate and improve defined glycan, glycopeptide, glycoprotein, and glycolipid microarrays, along with Luminex-based glycan-bead technologies, all unique to the resource. Aim 2- We will make available and further improve natural bifunctional fluorescent-tags (BFTs) originally pioneered by the NCFG, and will be utilized in glycan microarray and bead conjugations. Such novel BFTs, pioneered by the NCFG, give us advanced capabilities to label glycans in complex mixtures, purify them, and then quantify and quantitatively print microarrays at varying densities. Aim 3- We will continue to use BFT technology to produce and improve natural glycan microarrays from many sources of cells, tissues, and glycoconjugates, comprising a unique and valuable tool for the resource center. Thus, our Protein-Glycan Interaction Resource provides unique capabilities in glycan- binding expertise and technologies, teaching opportunities, and a wide range of services and outreach to an emerging field rapidly becoming recognized as a key factor in health and disease.